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Date:

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Time:

Thursday, 21 Sept 2023

Video-Recording for any system with MP4-support

- Video.mp4 (ca. 336 Mb)

15:15 – 16:20

"Visualizing Many Body Quantum States in Magical Flat Bands"

Prof. Ali Yazdani

(Princeton University)

Abstract:

When electrons live in electronic bands without any momentum dispersion

(flat bands), they are forced to interact strongly with one another. These

interactions can give rise to some of the most exotic electronic states

known to date, such as the fractional quantum Hall effect, which occur for

electrons moving in a plane subjected to strong magnetic fields. Recently,

there has been another method to create flat bands, by twisted stacking of

two-dimensional crystals and subjecting electrons to move in so-called

moiré potentials that forms in such structures. I will show how we use a

scanning tunneling microscope (STM) to visualize electronic states in two

related instances of electrons moving in the flat bands, when they make

correlated insulating phases. The microscopy experiments allow us to tease

out what type of correlated electronic states electron are forming and

show these state to have remarkable novel quantum texture in their

electronic wavefunctions.

Biography:

Ali Yazdani is Professor of Physics at Princeton University and the

Director of the Princeton Center for Complex Materials. He is a leading

expert in the development of quantum microscopy and spectroscopy

techniques to study unconventional states of matter. His awards include

Buckley Prize (2023), the most prestigious condensed matter physics prize

of the American Physical Society. He is a member of the US National

Academy of Sciences, Fellow of the American Academy of Arts and Sciences,

American Association for the Advancement of Science and of the American

Physical Society. Since 2015 he holds a ``Class of 1909'' Professorship of

Physics at Princeton University.

References:

https://www.science.org/doi/10.1126/science.abm3770

https://www.science.org/doi/10.1126/science.abn2049

https://www.nature.com/articles/s41567-023-02126-z

https://www.nature.com/articles/s41567-023-02134-z

https://www.nature.com/articles/s41586-023-06226-x